Burkert Type 8620 - Manual (Page 119)

mxCONTROL Type 8620
Page 119
14.6 Dosing of oxygen absorption media
14.6.1 Flow and temperature-based dosing
(O2_SCAV_CTRL_RATIO)
This module permits the dosing of oxygen-absorbing substances which are added to the hot water
as anti-corrosive, based on the flow and temperature of the feed water).
These modules
are explained
below.
Figure 55: O2_SCAV_CTRL_RATIO
Flow-temperature dosing control (FT dosing control)
Flow-temperature dosing control determines the output signal proportionally to the flow of the feed
water and the oxygen dissolved in it - see the following figure.
The oxygen content is determined via the temperature of the feed water (see section "
Oxygen concentration"). For the calculation, the actual flow value is converted into a scaled flow
0…100% whereby 0% corresponds to the low scaling value Scal- and 100% to the high scaling value
Scal+ of the flow input.
Control output = a * b with a … flow (scaled value)
b … oxygen concentration (scaled value)
Figure 56:
FT Dosing control